We love Ionic and have a medium-sized 1.X application that we want to migrate to Ionic 2 / Angular 2. Our 1.X code follows John Papa’s style guide with a lot of directives, relatively thin controllers, and a component-based directory layout.

Ng-upgrade is not a viable option for migration and Ionic 1 and 2 components cannot really co-exist

Will an upcoming Ionic 1.X release include Angular 1.5 to allow for migration to Angular 2.0 style components? Ionic v1.3.2 uses Angular 1.5.3, so this may be possible, but I haven’t tried it.

We looked at the Angular 1.5 approach but it seemed cleaner and easier to repurpose and re-implement everything to Ionic 2 from a fresh Ionic 2 starter project.

Though Angular 1 and 2 have the same name, they’re not the same language or framework at all. Typescript, object oriented programming, Ionic’s change from routing to a navcontroller, and the new build chain (with Ahead-of-time compilation) are all awesome improvements, but they make migration difficult.

If I had an existing Ionic 1 app that met requirements and didn’t require major functional enhancements, I wouldn’t rush to migrate to Ionic 2. We moved over to Angular 2 / Ionic 2 while doing a major redesign of the app, and we brought over some code (e.g. services and filters).

Ionic 2 is a much better framework and I’m really happy that we made the investment to switch over. It also positions us to expand our app into a web-based app (which could be quite fast with Ahead-of-Time compiling) and possibly tap into SEO-friendly approaches such as Angular Universal in the future.